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Updated: Aug 25, 2026
A Melanoma Patient-Derived Xenograft Model
Published on: May 20, 2019
CpG oligonucleotides elicit antitumor responses in a human melanoma NOD/SCID xenotransplantation model
Clemens Krepler1, Volker Wacheck, Sabine Strommer
1Department of Dermatology, Division of General Dermatology, University of Vienna, Austria.
Abstract:
For patients with advanced malignant melanoma, the 5 y survival rate with current treatment modalities is low. There is an urgent need for more effective therapeutic concepts. One approach with great potential is to stimulate the body's own immune defense to reject cancer cells using CpG oligonucleotides. Distinct oligonucleotides containing nonmethylated cytidine residues in cytidine-guanosine dinucleotides with particular flanking bases (CpG motifs) are capable of eliciting powerful immune stimulation by mimicking infectious disease. We evaluated the in vivo antitumoral effects of CpG oligonucleotides against human malignant melanoma xenografts in NOD/SCID mice. CpG oligonucleotides administered in single peritumoral subcutaneous injections three times per week resulted in elevated plasma levels of interleukin-12 and significant inhibition of the growth of established tumor xenografts by 60% (p<0.016) compared to the saline control. In addition to this a significant invasion of macrophages into tumor xenografts and increased numbers of Langerhans-cell-derived dendritic cells in draining lymph nodes could be observed. Our findings demonstrate the antitumor activity of oligonucleotides containing immune-stimulatory CpG motifs in a xenotransplantation model with absent B, T cells and a lack of natural killer cell function.
Insights
CpG oligonucleotides show promise in fighting advanced malignant melanoma by stimulating the immune system. This immunotherapy approach significantly inhibited tumor growth in a mouse model, offering a potential new treatment strategy.
Area of Science:
- Immunology
- Oncology
- Molecular Biology
Background:
- Advanced malignant melanoma has a low 5-year survival rate with current treatments.
- There is a critical need for novel and effective therapeutic strategies.
- CpG oligonucleotides can stimulate the immune system by mimicking infectious disease.
Purpose of the Study:
- To evaluate the in vivo antitumoral effects of CpG oligonucleotides against human malignant melanoma xenografts.
- To assess the immune response and tumor growth inhibition in a preclinical model.
Main Methods:
- Human malignant melanoma xenografts were established in NOD/SCID mice.
- CpG oligonucleotides were administered via peritumoral subcutaneous injections three times per week.
- Plasma levels of interleukin-12, tumor growth, and immune cell infiltration were analyzed.
Main Results:
- CpG oligonucleotide treatment led to elevated plasma levels of interleukin-12.
- A significant 60% inhibition of established tumor xenograft growth was observed compared to saline controls (p<0.016).
- Increased macrophage infiltration into tumors and enhanced numbers of dendritic cells in lymph nodes were noted.
Conclusions:
- Oligonucleotides containing immune-stimulatory CpG motifs demonstrate significant antitumor activity.
- This approach shows potential as a therapeutic strategy for malignant melanoma.
- The study highlights the efficacy in an immunodeficient xenotransplantation model.
